The European Union has fined Microsoft €561 million ($729 million) for not promoting rival web browsers to its Internet Explorer.

The European Union has fined Microsoft €561 million ($729 million) for not promoting rival web browsers to its Internet Explorer.

The Windows maker was previously in trouble with the EU over anti-competitive practises, eventually agreeing to introduce the Browser Choice Screen in March 2010 as part of a settlement.

However, Microsoft removed the choice in the Windows 7 Service Pack 1 update in February 2011, restoring Internet Explorer as the default browser. It was another 14 months before the feature was added in again, and only after receiving complaints from the EU. The company said this was due to a technical error, but that did not wash with European authorities.

The magically disappearing Browser Choice Screen

Joaquin Almunia, Competition Commission for the EU, said Microsoft's behaviour marked a “serious breach” of its prior commitment, and he hoped the fine would deter other companies from going back on their promise to act in a competitively fair manner. It seems the ruling was as much a warning to others as it was a reprimand of Microsoft itself.

While Microsoft will be upset at this latest fine, it could have been much worse. EU rules allow for fines of up to 10 percent of a company's annual revenue, which could have amounted to $7.4 billion for 2012. The firm's cooperation was seen as a mitigating factor in the punishment.

“We take full responsibility for the technical error that caused this problem and have apologised for it,” a Microsoft spokesperson said.